Refrigerators, depending on the positions of a refrigerator compartment and a freezer compartment, can be classified into a top mount refrigerator having a freezer compartment on the top and a refrigerator compartment on the bottom, a bottom freezer refrigerator having a refrigerator compartment on the top and a freezer compartment on the bottom, and a side-by-side refrigerator having a freezer compartment and a refrigerator compartment left and right.
In a side-by-side refrigerator, an evaporator is disposed in the rear portion of the freezer compartment and the air in the freezer compartment and the refrigerator compartment is sucked and sent to the evaporator from the bottoms of the compartments. Cold air produced through the evaporator is supplied into the refrigerator compartment and the freezer compartment through the top of the compartments.
The doors of refrigerators are generally rotatably coupled to the front of the refrigerators and when they are closed, their front exterior surfaces are exposed to their users. As refrigerator doors typically remain closed, highly aesthetic materials, including panels having various patterns, may be attached to the front sides of the refrigerator doors to enhance their aesthetic values.
Recently, users increasingly prefer to appliances having metallic simple external appearances. However, refrigerators have not only a display for users to be able to check the operating statuses, but a button unit for inputting operating conditions on the front sides of the doors, so it is not aesthetically preferable.
In consideration of this problem, recently, refrigerator doors having a structure that hides a display and operation button unit at normal times, but shows them only when a user wants to use them are being increasingly studied. This function is defined as so-called a hidden display or a hidden button in some cases.
It is typically difficult to apply a button of electrostatic touch type to refrigerator doors having metallic front panels due to leakage of static electricity. In addition, as metal is typically resistant to flexure, it may be difficult to apply a button of constant pressure type. Further, it may be difficult to achieve a metallic panel having hidden buttons particularly in the touch sensing type.
Accordingly, a sensor that can reliably sense a touch input even on a metallic panel is desired. Such a sensor can be used in various applications, including on the front panels for refrigerator doors and in other appliances having metallic outer structures to which hidden button of touch type can be applied.